The so-called computer “mouse,” and other pointing devices such as the trackball, touchpad and joystick, have allowed the computer industry to use the display monitor as a continuously variable control and data input device. This has made difficult computer concepts available and controllable by individuals not at all versed in the computer art.
There are situations, however, where the mouse is inconvenient and limiting to computer operation because of the necessity for the user to remove his/her hands from the keyboard, or to empty at least one hand from carrying an item in order to maneuver and actuate the “mouse.” Furthermore, it is usual to need to supply extra desktop space for this instrument and in many instances a special surface for it to operate properly.
Many innovations have been made to reduce the occurrence of contaminants entering the rolling mechanical element in a mouse or track ball such as use of optical and touch-sensitive devices. This does not remove the requirement, however, for changing hand position or emptying at least one hand to locate the “mouse” and maneuver it.
One type of application in particular where this occurs often is in the construction and use of spreadsheets such as the popular Microsoft application EXCEL, where navigation to spreadsheet cells and control panel functions are greatly enhanced with the “mouse” but at the same time cause the user to remove his/her hands from the keyboard, which is necessary for making alphanumeric entries into the cells. Other examples of this inconvenience also can be brought to mind.
Although there are myriad prior-art teachings on the computer mouse, track ball, touch panel, joystick and even 3D mouse, no existing system uses totally electronic motion trackers to achieve hands-off mouse functioning. The closest approach appears to be an optical IR unit designed to fit atop a computer monitor to track a reflective spot stuck to the user's forehead (see DynaSight™, a device trademarked by Origin Instrument Corp., www.orin.com, no patent cited). The DynaSight has obvious limitations in set-up, size, weight, mobility, ruggedness and power consumption compared to the current invention.
The original Engelbart mechanical mouse patent (U.S. Pat. No. 3,541,541) through optical-mechanical and optical and a recent packaging to relieve carpal tunnel syndrome called “The Quill” all require a hand to operate. One unit, called the “Nohands Mouse (U.S. Pat. No. 5,694,152),” consists of units placed on the floor under the operator's feet where light foot pressure from an elevated chair position manipulates the mouse and apparently also is of a mechanical nature. This approach could be a good solution for healthy, well-coordinated individuals, particularly if carpel tunnel were their problem, but the invention would be of little assistance to the physically challenged. Nor would this system or DynaSight be appropriate if the operator must stand or walk while operating a computer, especially a mobile unit such as a laptop computer or a computer made for wearing on the body such as in U.S. Pat. No. 5,305,244.
Such actions interrupt the speedy flow of keyboard operations, and leads to typing errors and delays. All too often the edge of the mouse pad is reached or another obstacle on the desk is encountered causing additional time to be spent. Furthermore, the moving mechanical parts of the typical mouse picks up dust and other contaminants that must be cleaned out periodically in order to restore proper operation. There also is contention that the mouse contributes to a painful wrist condition known as carpel tunnel syndrome for which various shapes of the mouse have been designed to alleviate.
Hands-free position and orientation tracking systems do exist. U.S. Pat. No. 4,737,794, the teachings of which are incorporated herein by reference, disclose a method and apparatus for determining remote object orientation and position with an electromagnetic coupling. A plurality of radiating antennas are provided for radiating electromagnetic energy. Each of the radiating antennas have independent components for defining a source reference coordinate frame. A transmitter is provided for applying electrical signals to the radiating antennas for generating a plurality of electromagnetic fields. The signals are multiplexed so that the fields are distinguishable from one another. A plurality of receiving antennas are disposed on a remote object for receiving the transmitted electromagnetic fields. The receiving antennas have a plurality of independent components for detecting the transmitted electromagnetic fields and defining a sensor reference coordinate frame. An analyzer is provided for receiving the output of the receiving antennas and converting the components of the transmitted electromagnetic fields into remote object position and orientation relative to the source reference coordinate frame.
The analyzing means includes means for processing the components of the electromagnetic fields independently into remote object position in Cartesian coordinates and remote object orientation using a quaternion processing strategy. The processing technique provides an uncoupled, non-iterative, closed form solution for both position and orientation which is fast and continuous. Further, in the case where dipole antennas are used and the size of the antennas is significant relative to the separation distance between the radiating and receiving antennas, an aperture compensation technique is provided for compensating for distortion in the dipole fields. Still further, the processing technique provides an arrangement for smoothing or filtering the solution for position and orientation by blending previous solutions into the current solution.
FIG. 1 is a diagram that illustrates three-dimensional (3D) head/helmet tracking using AC magnetics, wherein a transmitter couples signals to at least one sensor. Use of a dipole field model allows position and orientation (P&O) of the receiver/sensor to be determined with a single data sample. In actuality, the P&O is a relative computation between source and sensor, such that reciprocity holds true and it makes no difference which device is being tracked from the other as a reference. U.S. Pat. Nos. 6,369,564; 6,400,139; 6,624,626; and 6,762,600, each of which are also incorporated herein by reference, teach various techniques to overcome distortion in AC magnetic tracking systems.